Zero turn mower gearbox

[Elektrishun]

Family member contacted me asking if I could help them fix their zero turn mower. They said that the blades stopped turning and they seen smoke coming from the "motor" that turns the blades. After sending me some pictures I let them know that the "motor" that was smoking is a gearbox.

Never used a zero turn mower. How badly do you need to abuse it to get the gearbox to smoke? I'm guessing zero maintenance for the zero turn helps?

 

[DPittman]

If it is a consumer class zero turn mower like most of them at big box stores the transmissions are unserviceable and are all are destined for the junk pile sooner than I think they should.
I am not familiar with any mowers nowadays that have a gearbox that drives the blades but I guess that is very possible. I'd guess it's the belts that are smoking and may be because of something (spindles/bearings/clutch/transmission) that is piling up. Belts do wear and can slip causing a smoke show.

I recently had to replace a zero turn mower that had non serviceable transmissions in it and consequently they failed. Parts were no longer available and even when they were they were astronomicaly priced. I made sure the new replacement mower had serviceable transmissions.

 

[Elektrishun]

@DPittman

I suggested that before I make the trip out of town to the acreage maybe get a second opinion from their neighbor friend who might know what they're looking at. They had the neighbor who lives a few minutes away come over to inspect. Not the gearbox. You're thoughts were correct - the belt broke. Probably smoked first and then broke in the vicinity of the gearbox.

 

[140mower]

If it smoked first, somewhere down the line a bearing has likely seized, either in a spindle or one of the idler pulleys.

 

[Susquatch]

I find that sometimes a branch or something jams up in the belt path. If that stops the belt or reduces the tension, the belt can slip and then smoke.

Check for bad bearings, broken tension springs, foreign material in the belt path, incorrect deck position, and of course broken or bent pullies.

 

[Chicken lights]

If it smoked first, somewhere down the line a bearing has likely seized, either in a spindle or one of the idler pulleys.

It's likely V-belts on a mower- but have you ever had a serpentine belt chew itself off?

 

[Susquatch]

It's likely V-belts on a mower- but have you ever had a serpentine belt chew itself off?

I assume you don't mean a timing belt.

My 62in mower deck has three blades all driven by a huge serpentine belt. And yes, I've had it chew itself off several times. Turned out to be caused by a bouncing idler pulley that didn't have enough tension because the wrong spring was installed at the factory.

I knew something was wrong cuz it was too easy to replace the belt.

 

[Chicken lights]

I assume you don't mean a timing belt.

My 62in mower deck has three blades all driven by a huge serpentine belt. And yes, I've had it chew itself off several times. Turned out to be caused by a bouncing idler pulley that didn't have enough tension because the wrong spring was installed at the factory.

I knew something was wrong cuz it was too easy to replace the belt.

No, not a timing belt. Serpentine where the ribs go lengthwise.

One truck just ate belts no matter what I did, or fixed, or replaced. I even tried using a laser to line up the pulleys. I was just curious, the man's been around trucks a lot longer than I have

 

[140mower]

It's likely V-belts on a mower- but have you ever had a serpentine belt chew itself off?

I have, but only because of a seized idler..... Very few if any of the belts I have lost or fried were the fault of the belt, it's almost always heat buildup from slippage (either too loose or seized bearing) or poor alignment.
What was it on? I could see how if it was on one of International's power offerings it could likely chew it's self in half in order to escape....... 🙄 😛

 

[Chicken lights]

I have, but only because of a seized idler..... Very few if any of the belts I have lost or fried were the fault of the belt, it's almost always heat buildup from slippage (either too loose or seized bearing) or poor alignment.
What was it on? I could see how if it was on one of International's power offerings it could likely chew its self in half in order to escape....... 🙄 😛

an international 9900i with a Cummins 😛

It would slowly lose one rib at a time, I drove from downtown Toronto to Indiana once with 3-4 ribs left hanging on (new is likely 10 or 12 ribs). Had to be alignment but I couldn't figure it out

 

[Elektrishun]

@140mower and @Susquatch

All good thoughts and I have passed on the suggestions before they try out the new belt. Thanks

 

[Doggggboy]

Mower blade drive belt.
One of the blade hub bearings seized. If an idler pulley seizes usually the blades will keep turning but it will get noisier.
3 bolts, a new belt and you're golden again.